<template>
  <div id="message" v-scroll-bottom="sessions">
  	<ul v-if="currentSession">
  		<li v-for="entry in sessions[user.username+'#'+currentSession.username]">
  			<p class="time">
  				<span>{{entry.date | time}}</span>
  			</p>
  			<div class="main" :class="{self:entry.self}">
  				<img class="avatar" :src="entry.self ? user.userface : currentSession.userface" alt="">
  				<p class="text">{{entry.content}}</p>
  			</div>
  		</li>
  	</ul>
  </div>
</template>

<script>
import {mapState} from 'vuex'

export default {
  name: 'message',
  data () {
    return {
      user:JSON.parse(window.sessionStorage.getItem("user"))
    }
  },
  computed:mapState([
  	'sessions',
  	'currentSession'
  ]),
  filters:{
  	time (date) {
      if (date) {
        date = new Date(date);
      }
  		return `${date.getHours()}:${date.getMinutes()}`;
  	}
  },
  directives: {/*这个是vue的自定义指令,官方文档有详细说明*/
    // 发送消息后滚动到底部,这里无法使用原作者的方法，也未找到合理的方法解决，暂用setTimeout的方法模拟
    'scroll-bottom' (el) {
      //console.log(el.scrollTop);
      setTimeout(function () {
        el.scrollTop+=9999;
      },1)
    }
  }
}
</script>

<style lang="scss" scoped>
#message {
	padding: 15px;
  max-height: 68%;
  overflow-y: scroll;
  ul {
    padding-left: 0;
  	list-style-type: none;
  	li {
  		margin-bottom: 15px;
  	}
  }
  .time {
  	text-align: center;
  	margin: 7px 0;
  	> span {
  		display: inline-block;
  		padding: 0 18px;
  		font-size: 12px;
  		color: #FFF;
  		background-color: #dcdcdc;
  		border-radius: 2px;
  	}
  }
  .main {
  	.avatar {
  		float: left;
  		margin: 0 10px 0 0;
  		border-radius: 3px;
  		width: 30px;
  		height: 30px;

  	}
  	.text {
  		display: inline-block;
  		padding: 0 10px;
  		max-width: 80%;
  		background-color: #fafafa;
      border-radius: 4px;
      line-height: 30px;
  	}
  }
  .self {
    text-align: right;
    .avatar {
      float: right;
      margin: 0 0 0 10px;
      border-radius: 3px;
      width: 30px;
      height: 30px;
    }
    .text {
      display: inline-block;
      padding: 0 10px;
      max-width: 80%;
      background-color: #b2e281;
      border-radius: 4px;
      line-height: 30px;
    }
  }
}
</style>
